There is known a resin-encapsulated type electronic device including an electronic component, an encapsulating resin body that encapsulates the electronic component, a lead frame extended over the inside and outside of the encapsulating resin body, and a bonding wire that electrically connects the electronic component and the lead frame inside the encapsulating resin body. The lead frame includes an inner lead disposed inside the encapsulating resin body, and an outer lead connecting to the inner lead and protruding to the outside of the encapsulating resin body.
Patent Literature 1 discloses a resin-encapsulated type electronic device (semiconductor package) including a lead frame that is plated with multiple layers so as to restrict an encapsulating resin body from being peeled off from the lead frame and a bonding wire from being disconnected due to the peeling. In Patent Literature 1, the entire surface of the lead frame is subjected to Cu strike plating, then an outer lead is masked with a jig, and an inner lead is subjected to roughening Cu plating. Next, the front end of the inner lead is opened and subjected to Ag plating by using a jig masking the other portion.